PS101 Lecture Notes - Lecture 7: Basilar Membrane, Insular Cortex, Inner Ear
Document Summary
Ps 101 week 7 chapter 4 (pg 170-197) Sound must travel through some sort of medium (air). Wavelengths of sound are described in terms of their frequency, which is measured in cycles per second, or hertz. Humans can hear as low as 20 hz and high as 20 000 hz. Amplitude of sound (volume) is measured in decibels. Humans are most sensiive to sounds around 2000 hz. Purity of a sound inluences how imbre is perceived. Example: same loudness and pitch played on a french horn then on a violin. External ear depends on vibraion of air molecules. Middle ear depends on vibraions of moveable bones. Inner ear depends on waves in a luid. External ear consists mainly of the pinna, a sound-collecing cone. Sound waves collected by the pinna are funneled along the auditory canal toward the eardrum (membrane that vibrates in response).
